Structural, elastic, electronic and magnetic properties of ThCr2Si2 from first-principles calculations

The tetragonal (s.g. I4/mmmI4/mmm; #139) ThCr2Si2 is widely known as a structural type of the broad family of the so-called 122-like ternary phases which includes now more than 800 members. Among them the superconducting iron-pnictides AFe2Pn2 (discovered in 2008, A=alkali-earth metals) and the newest superconducting iron-chalcogenides A′Fe2Ch2 (discovered in 2010, A′=alkali metals) have attracted recently enormous interest in this class of materials. Meanwhile, the data about the electronic, magnetic, and elastic properties of the ThCr2Si2 phase itself are still practically absent. Here, by means of first-principles calculations, the optimized structural parameters, spin ordering of the magnetic ground state, independent elastic constants, bulk, shear, and Young’s moduli, elastic anisotropy indexes, total and partial densities of states, and inter-atomic bonding picture for ThCr2Si2 were obtained for the first time and analyzed in comparison with the aforementioned most popular 122-like systems AFe2Pn2 and A′Fe2Ch2.

► ThCr2Si2 is a structural type of the so-called 122-like ternary phases.
► Elastic, magnetic and electronic properties for ThCr2Si2 are predicted.
► ThCr2Si2 should be assumed as a 3D-like system owing to Si–Si inter-block bonds.
► The properties of ThCr2Si2 are analyzed in comparison with AFe2Pn2 and AFe2Ch2.